The presence of nanomaterials (NMs) in the environment may represent a serious risk to human heal... more The presence of nanomaterials (NMs) in the environment may represent a serious risk to human health, especially in a scenario of chronic exposure. To evaluate the potential relationship between NM-induced epigenetic alterations and carcinogenesis, the present study analyzed a panel of 33 miRNAs related to the cell transformation process in BEAS-2B cells transformed by TiO2NP and long-term MWCNT exposure. Our battery revealed a large impact on miRNA expression profiling in cells exposed to both NMs. From this analysis, a small set of five miRNAs (miR-23a, miR-25, miR-96, miR-210, and miR-502) were identified as informative biomarkers of the transforming effects induced by NM exposures. The usefulness of this reduced miRNA battery was further validated in other previously generated transformed cell systems by long-term exposure to other NMs (CoNP, ZnONP, MSiNP, and CeO2NP). Interestingly, the five selected miRNAs were consistently overexpressed in all cell lines and NMs tested. These ...
Arsenic induces oncogenic effects activating stress-related signalling pathways. This can result ... more Arsenic induces oncogenic effects activating stress-related signalling pathways. This can result in the over-activation of the AP-1 protein, specifically its FRA1 component. FRA1 is a transcription factor frequently overexpressed in epithelial tumors, where it can regulate the expression of different target genes. Accordingly, FRA1 could play an essential role in the in vitro cell transformation induced by arsenic. FRA1 levels were monitored in MEF cells throughout their transformation stages during 40 weeks of long-term 2 μM arsenic exposure. Interestingly, the results show a progressive FRA1 overexpression with time (60-fold and 11-fold for mRNA and pFRA/non-pFRA1, respectively, at week 40), which may be responsible for the observed altered expression in the FRA1 downstream target genes Pten, Pdcd4, Tpm1, Tgfb1, Tgfb2, Zeb1, Zeb2, and Twist. The levels of MAPKs (ERK, p38, and JNK) and other known players upstream from FRA1 were assessed at equivalent time-points, and ERK, p38 and ...
Background The increasing accumulation of plastic waste and the widespread presence of its deriva... more Background The increasing accumulation of plastic waste and the widespread presence of its derivatives, micro- and nanoplastics (MNPLs), call for an urgent evaluation of their potential health risks. In the environment, MNPLs coexist with other known hazardous contaminants and, thus, an interesting question arises as to whether MNPLs can act as carriers of such pollutants, modulating their uptake and their harmful effects. In this context, we have examined the interaction and joint effects of two relevant water contaminants: arsenic and polystyrene nanoplastics (PSNPLs), this last being a model of nanoplastic. Methods Since both agents are persistent pollutants, the potential effects have been evaluated under a chronic exposure scenario and measuring different effect biomarkers involved in the cell transformation process. Thus, cells previously transformed by chronic arsenic exposure were further exposed to PSNPLs, arsenic, and the combination PSNPLs/arsenic for 12 weeks. Results In...
In spite of its pioneer use in detecting mutational processes, Drosophila still plays an importan... more In spite of its pioneer use in detecting mutational processes, Drosophila still plays an important role in those studies aiming to detect and quantify the induction of DNA damage. Here we describe two assays, one detecting primary damage (the Comet assay) and the other detecting somatic mutation and recombination effects (wing-spot test). It is important to emphasize that somatic recombination is a key event in cancer development and no assays exist at present to detect and quantify somatic recombination processes, other than the spot tests developed in Drosophila.
Environmental plastic wastes are continuously degraded to their micro and nanoforms. Since in the... more Environmental plastic wastes are continuously degraded to their micro and nanoforms. Since in the environment they coexist with other pollutants, it has been suggested that they could act as vectors transporting different toxic trace elements, such as metals. To confirm this, we have assessed the potential interactions between nanopolystyrene, as a model of nanoplastic debris, and silver compounds (silver nanoparticles and silver nitrate), as models of metal contaminant. Using TEM-EDX methodological approaches, we have been able to demonstrate metal sorption by nanopolystyrene. Furthermore, using Caco-2 cells and confocal microscopy, we have observed the co-localization of nanopolystyrene/nanosilver in different cellular compartments, including the cell nucleus. Although the internalization of these complexes showed no exacerbated cytotoxic effects, compared to the effects of each compound alone, the silver/nanopolystyrene complexes modulate the cell’s uptake of silver and slightly ...
Accumulation of plastic and its derivatives, micro- and nanoplastics (MNPLs), is a substantial en... more Accumulation of plastic and its derivatives, micro- and nanoplastics (MNPLs), is a substantial environmental and ecological problem that could potentially become a serious health concern to humans.
Arsenic is considered a worldwide pollutant that can be present in drinking water. Arsenic exposu... more Arsenic is considered a worldwide pollutant that can be present in drinking water. Arsenic exposure is associated with various diseases, including cancer. Antioxidants as selenite and α-tocopherol-succinate have been shown to modulate arsenic toxic effects. Since changes in STAT3 and PSMD10 gene expression have been associated with carcinogenesis, the aim of this study was to evaluate the effect of arsenic exposure and co-treatments with selenite or α-tocopherol-succinate on the expression of these genes, in the livers of chronically exposed Syrian golden hamsters. Animals were divided into six groups: (i) control, (ii) chronically treated with 100 ppm arsenic, (iii) treated with 6 ppm α-tocopherol-succinate (α-TOS), (iv) treated with 8.5 ppm selenite, (v) treated with arsenic + α-TOS, and (vi) treated with arsenic + selenite. Urine samples and livers were collected after 20 weeks of continuous exposure. The urine samples were analyzed for arsenic species by atomic absorption spectr...
Nanomaterials in general and cobalt nanoparticles (CoNPs) in particular are of great interest not... more Nanomaterials in general and cobalt nanoparticles (CoNPs) in particular are of great interest not only because of their multiple applications and environmental impact, but also for their potential toxicity and safety issues.
Thousands of nanomaterials (NMs)-containing products are currently under development or incorpora... more Thousands of nanomaterials (NMs)-containing products are currently under development or incorporated in the consumer market, despite our very limited understanding of their genotoxic potential. Taking into account that the toxicity and genotoxicity of NMs strongly depend on their physicochemical characteristics, many variables must be considered in the safety evaluation of each given NM. In this scenario, the challenge is to establish high-throughput methodologies able to generate rapid and robust genotoxicity data that can be used to critically assess and/or predict the biological effects associated with those NMs being under development or already present in the market. In this study, we have evaluated the advantages of using a flow cytometry-based approach testing micronucleus (MNs) induction (FCMN assay). In the frame of the EU NANoREG project, we have tested six different NMs—namely NM100 and NM101 (TiO2NPs), NM110 (ZnONPs), NM212 (CeO2NPs), NM300K (AgNPs) and NM401 (multi-wall...
The widespread use of titanium dioxide nanoparticles (TiO NPs) in commercial food products makes ... more The widespread use of titanium dioxide nanoparticles (TiO NPs) in commercial food products makes intestinal cells a suitable target. Accordingly, we have used the human colon adenocarcinoma Caco-2 cells to detect their potential harmful effects. Caco-2 cells can differentiate in to enterocytic-like cells, forming consistent cell monolayers and are used as a model of the intestinal barrier. Using both undifferentiated and differentiated Caco-2 cells, we have explored a set of biomarkers, aiming to evaluate undesirable effects associated to TiO NP exposure. Results indicate non-toxic effects in exposures ranging 1-200 μg ml . Significant differences were observed in cell uptake, with a higher amount of incorporated TiO NPs in undifferentiated cells, as visualized using confocal microscopy. In well-established monolayers, translocation was detected using both confocal microscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy. In spite of the observed upt...
High aspect ratio nanomaterials (NM) have a promising future in medicine and industry as a unique... more High aspect ratio nanomaterials (NM) have a promising future in medicine and industry as a unique category of NM. Consequently, it is important to evaluate their potential biological side-effects before crediting their use. To understand the mechanisms of degradation, internalisation, and interaction with different biological targets, we used the in vivo model Drosophila melanogaster to obtain a systematic and complete study on high aspect ratio Ni nanowires (NiNW), compared with low aspect ratio Ni nanospheres (NiNS), and NiSO as a model of agent releasing nickel ions. The distinguished shape of nanowires showed changes in their characteristics after oral administration until they reached the intestinal lumen, where their diameter decreased significantly. For the first time, we confirmed the internalization of needle-shaped materials via perforation of the intestinal barrier. Moreover, the results showed that D. melanogaster is a valid and effective tool in studies related to magne...
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2018
Since ingestion is one of the main routes of entry of nanoparticles (NPs) in our organism, simple... more Since ingestion is one of the main routes of entry of nanoparticles (NPs) in our organism, simple and fast in vitro models of the intestinal barrier can be helpful to evaluate NPs risk. The human colon adenocarcinoma Caco-2 cell line has been extensively used due to its ability to differentiate, forming a well-structured cell monolayer. In this study, we have used these differentiated cells as a model of intestinal barrier to evaluate a wide set of effects caused by exposure to silver nanoparticles (AgNPs) with an average size of 7.74 nm. Different parameters such as toxicity, monolayer integrity and permeability (assessed by changes in cells' morphology and gene expression pattern), internalization (uptake), translocation, and induction of DNA damage (DNA breaks and oxidative DNA damage) were evaluated. No significant effects were observed on the monolayer's integrity/permeability after exposure to silver nanoparticles, although cellular uptake was demonstrated by using con...
The biological effects of nanoparticles depend on several characteristics such as size and shape ... more The biological effects of nanoparticles depend on several characteristics such as size and shape that must be taken into account in any type of assessment. The increased use of titanium dioxide nanoparticles (TiONPs) for industrial applications, and specifically as a food additive, demands a deep assessment of their potential risk for humans, including their abilities to cross biological barriers. We have investigated the interaction of three differently shaped TiONPs (nanospheres, nanorods and nanowires) in an in vitro model of the intestinal barrier, where the coculture of Caco-2/HT29 cells confers inherent intestinal epithelium characteristics to the model (i.e. mucus secretion, brush border, tight junctions, etc.). Adverse effects in the intestinal epithelium were detected by studying the barrier's integrity (TEER), permeability (LY) and changes in the gene expression of selected specific markers. Using Laser Scanning Confocal Microscopy, we detected a different behaviour in...
Toxicology in vitro : an international journal published in association with BIBRA, Jan 23, 2017
The most plausible exposure route to manufactured nanomaterials (MNM) remains pulmonary inhalatio... more The most plausible exposure route to manufactured nanomaterials (MNM) remains pulmonary inhalation. Yet, few studies have attempted to assess carcinogenic properties in vitro following long-term exposure of human pulmonary cells to low and occupationally relevant doses. The most advanced in vitro tests for carcinogenicity, the cell transformation assay (CTA), rely mostly on rodent cells and short-term exposure. We hypothesized that long-term exposure of human bronchial epithelial cells with a normal phenotype could be a valuable assay for testing carcinogenicity of nanomaterials. Therefore, this study (performed within the framework of the FP7-NANoREG project) assessed carcinogenic potential of chronic exposure (up to 6months) to low doses of multi-walled carbon nanotubes (MWCNT, NM-400 and NM-401) and TiO2 materials (NM62002 and KC7000). In order to harmonize and standardize the experiments, standard operating protocols of MNM dispersion (NANOGENOTOX) were used by three different N...
The biological reactivity of metal and metal oxide nanomaterials is attributed to their redox pro... more The biological reactivity of metal and metal oxide nanomaterials is attributed to their redox properties, which would explain their pro- or anti-cancer properties depending on exposure circumstances. In this sense, copper oxide nanoparticles (CuONP) have been proposed as a potential anti-tumoral agent. The aim of this study was to assess if CuONP can exert antigenotoxic effects using Drosophila melanogaster as an in vivo model. Genotoxicity was induced by two well-known genotoxic compounds, namely potassium dichromate (PD) and ethyl methanesulfonate (EMS). The wing-spot assay and the comet assay were used as biomarkers of genotoxic effects. In addition, changes in the expression of Ogg1 and Sod genes were determined. The effects of CuONP cotreatment were compared with those induced by copper sulfate (CS), an agent releasing copper ions. Using the wing-spot assay, CuONP and CS were not able to reduce the genotoxic effects of EMS exposure, but had the ability to decrease the effects i...
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2017
End-stage renal disease patients present oxidative stress status that increases when they are sub... more End-stage renal disease patients present oxidative stress status that increases when they are submitted to hemodialysis (HD). This increase in oxidative stress can affect their genetic material, among other targets. The objective of this study was to evaluate the effect of using polysulfone membranes coated with vitamin E, during the HD sessions, on the levels of genetic damage of HD patients. Forty-six patients were followed for 6 months, of whom 29 changed from conventional HD to the use of membranes coated with vitamin E. The level of genetic damage was measured using the micronucleus and the comet assays, both before and after the follow-up period. Serum vitamin E concentration was also checked. The obtained results showed that 24% of our patients presented vitamin E deficiency, and this was normalized in those patients treated with vitamin E-coated membranes. Patients with vitamin E deficiency showed higher levels of oxidative DNA damage. After the use of vitamin E-coated membranes we detected a significant decrease in the levels of oxidative damage. Additionally, hemoglobin values increased significantly with the use of vitamin E-coated membranes. In conclusion, the use of vitamin E-coated membranes supposes a decrease on the levels of oxidative DNA damage, and improves the uremic anemia status. Furthermore, the use of this type of membrane was also effective in correcting vitamin E deficiency.
Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring ... more Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring but also for their antimicrobial activities. These activities are mainly derived from the organosulfur compounds (OSCs). Propyl propane thiosulfinate (PTS) is an OSC with potential use in the active packaging, but its safety should be guaranteed before being commercialized. The aim of this work was to investigate for the first time the cytotoxicity of PTS as well as its in vitro mutagenic/genotoxic potential using the following battery of genotoxicity tests:(1)the bacterial reverse-mutation assay in S. typhimurium (Ames test, OECD 471, 1997); (2) the micronucleus test (MN, OECD 487, 2016); (3) the mouse lymphoma thymidine-kinase assay (MLA, OECD 476, 2015), and (4) the comet assay (standard and modified with restriction enzymes). The results revealed that PTS was not mutagenic neither in the Ames test nor in MLA. However, genotoxic effects were recorded in the MN test on mammalian cells (L5178YTk(+/-)cells) after PTS exposure at the highest concentration tested (17.25 μM) without S9, and also its metabolites (+S9, from 20 μM). Moreover, in the comet assay, PTS induced DNA breaks damage in Caco-2 cells at the highest concentration tested (280 μM) but it did not induce oxidative DNA damage.
The presence of nanomaterials (NMs) in the environment may represent a serious risk to human heal... more The presence of nanomaterials (NMs) in the environment may represent a serious risk to human health, especially in a scenario of chronic exposure. To evaluate the potential relationship between NM-induced epigenetic alterations and carcinogenesis, the present study analyzed a panel of 33 miRNAs related to the cell transformation process in BEAS-2B cells transformed by TiO2NP and long-term MWCNT exposure. Our battery revealed a large impact on miRNA expression profiling in cells exposed to both NMs. From this analysis, a small set of five miRNAs (miR-23a, miR-25, miR-96, miR-210, and miR-502) were identified as informative biomarkers of the transforming effects induced by NM exposures. The usefulness of this reduced miRNA battery was further validated in other previously generated transformed cell systems by long-term exposure to other NMs (CoNP, ZnONP, MSiNP, and CeO2NP). Interestingly, the five selected miRNAs were consistently overexpressed in all cell lines and NMs tested. These ...
Arsenic induces oncogenic effects activating stress-related signalling pathways. This can result ... more Arsenic induces oncogenic effects activating stress-related signalling pathways. This can result in the over-activation of the AP-1 protein, specifically its FRA1 component. FRA1 is a transcription factor frequently overexpressed in epithelial tumors, where it can regulate the expression of different target genes. Accordingly, FRA1 could play an essential role in the in vitro cell transformation induced by arsenic. FRA1 levels were monitored in MEF cells throughout their transformation stages during 40 weeks of long-term 2 μM arsenic exposure. Interestingly, the results show a progressive FRA1 overexpression with time (60-fold and 11-fold for mRNA and pFRA/non-pFRA1, respectively, at week 40), which may be responsible for the observed altered expression in the FRA1 downstream target genes Pten, Pdcd4, Tpm1, Tgfb1, Tgfb2, Zeb1, Zeb2, and Twist. The levels of MAPKs (ERK, p38, and JNK) and other known players upstream from FRA1 were assessed at equivalent time-points, and ERK, p38 and ...
Background The increasing accumulation of plastic waste and the widespread presence of its deriva... more Background The increasing accumulation of plastic waste and the widespread presence of its derivatives, micro- and nanoplastics (MNPLs), call for an urgent evaluation of their potential health risks. In the environment, MNPLs coexist with other known hazardous contaminants and, thus, an interesting question arises as to whether MNPLs can act as carriers of such pollutants, modulating their uptake and their harmful effects. In this context, we have examined the interaction and joint effects of two relevant water contaminants: arsenic and polystyrene nanoplastics (PSNPLs), this last being a model of nanoplastic. Methods Since both agents are persistent pollutants, the potential effects have been evaluated under a chronic exposure scenario and measuring different effect biomarkers involved in the cell transformation process. Thus, cells previously transformed by chronic arsenic exposure were further exposed to PSNPLs, arsenic, and the combination PSNPLs/arsenic for 12 weeks. Results In...
In spite of its pioneer use in detecting mutational processes, Drosophila still plays an importan... more In spite of its pioneer use in detecting mutational processes, Drosophila still plays an important role in those studies aiming to detect and quantify the induction of DNA damage. Here we describe two assays, one detecting primary damage (the Comet assay) and the other detecting somatic mutation and recombination effects (wing-spot test). It is important to emphasize that somatic recombination is a key event in cancer development and no assays exist at present to detect and quantify somatic recombination processes, other than the spot tests developed in Drosophila.
Environmental plastic wastes are continuously degraded to their micro and nanoforms. Since in the... more Environmental plastic wastes are continuously degraded to their micro and nanoforms. Since in the environment they coexist with other pollutants, it has been suggested that they could act as vectors transporting different toxic trace elements, such as metals. To confirm this, we have assessed the potential interactions between nanopolystyrene, as a model of nanoplastic debris, and silver compounds (silver nanoparticles and silver nitrate), as models of metal contaminant. Using TEM-EDX methodological approaches, we have been able to demonstrate metal sorption by nanopolystyrene. Furthermore, using Caco-2 cells and confocal microscopy, we have observed the co-localization of nanopolystyrene/nanosilver in different cellular compartments, including the cell nucleus. Although the internalization of these complexes showed no exacerbated cytotoxic effects, compared to the effects of each compound alone, the silver/nanopolystyrene complexes modulate the cell’s uptake of silver and slightly ...
Accumulation of plastic and its derivatives, micro- and nanoplastics (MNPLs), is a substantial en... more Accumulation of plastic and its derivatives, micro- and nanoplastics (MNPLs), is a substantial environmental and ecological problem that could potentially become a serious health concern to humans.
Arsenic is considered a worldwide pollutant that can be present in drinking water. Arsenic exposu... more Arsenic is considered a worldwide pollutant that can be present in drinking water. Arsenic exposure is associated with various diseases, including cancer. Antioxidants as selenite and α-tocopherol-succinate have been shown to modulate arsenic toxic effects. Since changes in STAT3 and PSMD10 gene expression have been associated with carcinogenesis, the aim of this study was to evaluate the effect of arsenic exposure and co-treatments with selenite or α-tocopherol-succinate on the expression of these genes, in the livers of chronically exposed Syrian golden hamsters. Animals were divided into six groups: (i) control, (ii) chronically treated with 100 ppm arsenic, (iii) treated with 6 ppm α-tocopherol-succinate (α-TOS), (iv) treated with 8.5 ppm selenite, (v) treated with arsenic + α-TOS, and (vi) treated with arsenic + selenite. Urine samples and livers were collected after 20 weeks of continuous exposure. The urine samples were analyzed for arsenic species by atomic absorption spectr...
Nanomaterials in general and cobalt nanoparticles (CoNPs) in particular are of great interest not... more Nanomaterials in general and cobalt nanoparticles (CoNPs) in particular are of great interest not only because of their multiple applications and environmental impact, but also for their potential toxicity and safety issues.
Thousands of nanomaterials (NMs)-containing products are currently under development or incorpora... more Thousands of nanomaterials (NMs)-containing products are currently under development or incorporated in the consumer market, despite our very limited understanding of their genotoxic potential. Taking into account that the toxicity and genotoxicity of NMs strongly depend on their physicochemical characteristics, many variables must be considered in the safety evaluation of each given NM. In this scenario, the challenge is to establish high-throughput methodologies able to generate rapid and robust genotoxicity data that can be used to critically assess and/or predict the biological effects associated with those NMs being under development or already present in the market. In this study, we have evaluated the advantages of using a flow cytometry-based approach testing micronucleus (MNs) induction (FCMN assay). In the frame of the EU NANoREG project, we have tested six different NMs—namely NM100 and NM101 (TiO2NPs), NM110 (ZnONPs), NM212 (CeO2NPs), NM300K (AgNPs) and NM401 (multi-wall...
The widespread use of titanium dioxide nanoparticles (TiO NPs) in commercial food products makes ... more The widespread use of titanium dioxide nanoparticles (TiO NPs) in commercial food products makes intestinal cells a suitable target. Accordingly, we have used the human colon adenocarcinoma Caco-2 cells to detect their potential harmful effects. Caco-2 cells can differentiate in to enterocytic-like cells, forming consistent cell monolayers and are used as a model of the intestinal barrier. Using both undifferentiated and differentiated Caco-2 cells, we have explored a set of biomarkers, aiming to evaluate undesirable effects associated to TiO NP exposure. Results indicate non-toxic effects in exposures ranging 1-200 μg ml . Significant differences were observed in cell uptake, with a higher amount of incorporated TiO NPs in undifferentiated cells, as visualized using confocal microscopy. In well-established monolayers, translocation was detected using both confocal microscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy. In spite of the observed upt...
High aspect ratio nanomaterials (NM) have a promising future in medicine and industry as a unique... more High aspect ratio nanomaterials (NM) have a promising future in medicine and industry as a unique category of NM. Consequently, it is important to evaluate their potential biological side-effects before crediting their use. To understand the mechanisms of degradation, internalisation, and interaction with different biological targets, we used the in vivo model Drosophila melanogaster to obtain a systematic and complete study on high aspect ratio Ni nanowires (NiNW), compared with low aspect ratio Ni nanospheres (NiNS), and NiSO as a model of agent releasing nickel ions. The distinguished shape of nanowires showed changes in their characteristics after oral administration until they reached the intestinal lumen, where their diameter decreased significantly. For the first time, we confirmed the internalization of needle-shaped materials via perforation of the intestinal barrier. Moreover, the results showed that D. melanogaster is a valid and effective tool in studies related to magne...
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2018
Since ingestion is one of the main routes of entry of nanoparticles (NPs) in our organism, simple... more Since ingestion is one of the main routes of entry of nanoparticles (NPs) in our organism, simple and fast in vitro models of the intestinal barrier can be helpful to evaluate NPs risk. The human colon adenocarcinoma Caco-2 cell line has been extensively used due to its ability to differentiate, forming a well-structured cell monolayer. In this study, we have used these differentiated cells as a model of intestinal barrier to evaluate a wide set of effects caused by exposure to silver nanoparticles (AgNPs) with an average size of 7.74 nm. Different parameters such as toxicity, monolayer integrity and permeability (assessed by changes in cells' morphology and gene expression pattern), internalization (uptake), translocation, and induction of DNA damage (DNA breaks and oxidative DNA damage) were evaluated. No significant effects were observed on the monolayer's integrity/permeability after exposure to silver nanoparticles, although cellular uptake was demonstrated by using con...
The biological effects of nanoparticles depend on several characteristics such as size and shape ... more The biological effects of nanoparticles depend on several characteristics such as size and shape that must be taken into account in any type of assessment. The increased use of titanium dioxide nanoparticles (TiONPs) for industrial applications, and specifically as a food additive, demands a deep assessment of their potential risk for humans, including their abilities to cross biological barriers. We have investigated the interaction of three differently shaped TiONPs (nanospheres, nanorods and nanowires) in an in vitro model of the intestinal barrier, where the coculture of Caco-2/HT29 cells confers inherent intestinal epithelium characteristics to the model (i.e. mucus secretion, brush border, tight junctions, etc.). Adverse effects in the intestinal epithelium were detected by studying the barrier's integrity (TEER), permeability (LY) and changes in the gene expression of selected specific markers. Using Laser Scanning Confocal Microscopy, we detected a different behaviour in...
Toxicology in vitro : an international journal published in association with BIBRA, Jan 23, 2017
The most plausible exposure route to manufactured nanomaterials (MNM) remains pulmonary inhalatio... more The most plausible exposure route to manufactured nanomaterials (MNM) remains pulmonary inhalation. Yet, few studies have attempted to assess carcinogenic properties in vitro following long-term exposure of human pulmonary cells to low and occupationally relevant doses. The most advanced in vitro tests for carcinogenicity, the cell transformation assay (CTA), rely mostly on rodent cells and short-term exposure. We hypothesized that long-term exposure of human bronchial epithelial cells with a normal phenotype could be a valuable assay for testing carcinogenicity of nanomaterials. Therefore, this study (performed within the framework of the FP7-NANoREG project) assessed carcinogenic potential of chronic exposure (up to 6months) to low doses of multi-walled carbon nanotubes (MWCNT, NM-400 and NM-401) and TiO2 materials (NM62002 and KC7000). In order to harmonize and standardize the experiments, standard operating protocols of MNM dispersion (NANOGENOTOX) were used by three different N...
The biological reactivity of metal and metal oxide nanomaterials is attributed to their redox pro... more The biological reactivity of metal and metal oxide nanomaterials is attributed to their redox properties, which would explain their pro- or anti-cancer properties depending on exposure circumstances. In this sense, copper oxide nanoparticles (CuONP) have been proposed as a potential anti-tumoral agent. The aim of this study was to assess if CuONP can exert antigenotoxic effects using Drosophila melanogaster as an in vivo model. Genotoxicity was induced by two well-known genotoxic compounds, namely potassium dichromate (PD) and ethyl methanesulfonate (EMS). The wing-spot assay and the comet assay were used as biomarkers of genotoxic effects. In addition, changes in the expression of Ogg1 and Sod genes were determined. The effects of CuONP cotreatment were compared with those induced by copper sulfate (CS), an agent releasing copper ions. Using the wing-spot assay, CuONP and CS were not able to reduce the genotoxic effects of EMS exposure, but had the ability to decrease the effects i...
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2017
End-stage renal disease patients present oxidative stress status that increases when they are sub... more End-stage renal disease patients present oxidative stress status that increases when they are submitted to hemodialysis (HD). This increase in oxidative stress can affect their genetic material, among other targets. The objective of this study was to evaluate the effect of using polysulfone membranes coated with vitamin E, during the HD sessions, on the levels of genetic damage of HD patients. Forty-six patients were followed for 6 months, of whom 29 changed from conventional HD to the use of membranes coated with vitamin E. The level of genetic damage was measured using the micronucleus and the comet assays, both before and after the follow-up period. Serum vitamin E concentration was also checked. The obtained results showed that 24% of our patients presented vitamin E deficiency, and this was normalized in those patients treated with vitamin E-coated membranes. Patients with vitamin E deficiency showed higher levels of oxidative DNA damage. After the use of vitamin E-coated membranes we detected a significant decrease in the levels of oxidative damage. Additionally, hemoglobin values increased significantly with the use of vitamin E-coated membranes. In conclusion, the use of vitamin E-coated membranes supposes a decrease on the levels of oxidative DNA damage, and improves the uremic anemia status. Furthermore, the use of this type of membrane was also effective in correcting vitamin E deficiency.
Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring ... more Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring but also for their antimicrobial activities. These activities are mainly derived from the organosulfur compounds (OSCs). Propyl propane thiosulfinate (PTS) is an OSC with potential use in the active packaging, but its safety should be guaranteed before being commercialized. The aim of this work was to investigate for the first time the cytotoxicity of PTS as well as its in vitro mutagenic/genotoxic potential using the following battery of genotoxicity tests:(1)the bacterial reverse-mutation assay in S. typhimurium (Ames test, OECD 471, 1997); (2) the micronucleus test (MN, OECD 487, 2016); (3) the mouse lymphoma thymidine-kinase assay (MLA, OECD 476, 2015), and (4) the comet assay (standard and modified with restriction enzymes). The results revealed that PTS was not mutagenic neither in the Ames test nor in MLA. However, genotoxic effects were recorded in the MN test on mammalian cells (L5178YTk(+/-)cells) after PTS exposure at the highest concentration tested (17.25 μM) without S9, and also its metabolites (+S9, from 20 μM). Moreover, in the comet assay, PTS induced DNA breaks damage in Caco-2 cells at the highest concentration tested (280 μM) but it did not induce oxidative DNA damage.
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